The invention relates to a concealed guide rail assembly, in particular for drawers, comprising on each side of the drawer a pull-out rail to be attached to the drawer and a supporting rail to be attached to the furniture body, the load of the drawer being transmitted by cylindrical runner rollers which are mounted in a runner carriage in adjacent arrangement and which are arranged at least substantially in one horizontal plane, the runner carriages being provided with locking latches or the like which secure the carriages in one of the rail pairs when the supporting and pull-out rails are separated from each other.